Asus Crosshair V Formula/ThunderBolt - Manual (Page 168)

4-34 Chapter 4: Software support
Audio.input
Click the corresponding box to select from Mic and Line-In for the input device.
Click each button directly to configure the related settings.
Xear Surround Effect
Click Headphone and select Xear Surround Effect to enable the Xear
Surround Effect.
Ensure to select a proper Room Size for a better surround effect.